necrox-5 and Inflammation

This study aimed to evaluate the role of NecroX-5, a powerful anti-inflammatory agent, on the functional plasticity of macrophages and the possible underlying mechanism using RAW264.7 cells, thioglycollate-elicited peritoneal macrophages from C57BL/6 mice, and a murine model of dextran sodium sulfate (DSS)-induced colitis. The change in cell morphology was examined by scanning electron microscopy. The expression of CD206, arginase (Arg)-1, and inducible nitric oxide synthase (iNOS) were examined by western blotting. The production of inflammatory cytokines was detected by enzyme-linked immunosorbent assays and statistical comparisons were made. The results showed that treatment of RAW264.7 cells with NecroX-5 caused an elongated shape in comparison to non-treated cells. The expression levels of macrophage mannose receptor CD206 and Arg-1, specific markers of M2 cells, were significantly upregulated by NecroX-5 treatment, while those of iNOS (M1 macrophages) was decreased. In addition, NecroX-5 significantly reduced the secretion of inflammatory cytokines, while interleukin (IL)-4 and IL-13 secretion in the supernatant was significantly enhanced. Treatment with NecroX-5 considerably ameliorated the progression of DSS-induced colitis and significantly inhibited the mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor-α and IL-1β. Taken together, our findings demonstrated that NecroX-5 might dampen inflammation by switching the M1 phenotype to the M2 phenotype due to IL-4 and IL-13 induction.

Topics: Animals; Anti-Inflammatory Agents; Cell Differentiation; Cell Plasticity; Colitis; Cytokines; Dextran Sulfate; Disease Models, Animal; Heterocyclic Compounds, 4 or More Rings; Humans; Inflammation; Inflammation Mediators; Macrophages; Male; Mice; Mice, Inbred C57BL; RAW 264.7 Cells; Sulfones; Th2 Cells

Abnormality in mitochondria has been suggested to be associated with development of allergic airway disorders. In this study, to evaluate the relationship between mitochondrial reactive oxygen species (ROS) and NLRP3 inflammasome activation in allergic asthma, we used a newly developed mitochondrial ROS inhibitor, NecroX-5. NecroX-5 reduced the increase of mitochondrial ROS generation in airway inflammatory cells, as well as bronchial epithelial cells, NLRP3 inflammasome activation, the nuclear translocation of nuclear factor-κB, increased expression of various inflammatory mediators and pathophysiological features of allergic asthma in mice. Finally, blockade of IL-1β substantially reduced airway inflammation and hyperresponsiveness in the asthmatic mice. These findings suggest that mitochondrial ROS have a critical role in the pathogenesis of allergic airway inflammation through the modulation of NLRP3 inflammasome activation, providing a novel role of airway epithelial cells expressing NLRP3 inflammasome as an immune responder.

Topics: Animals; Asthma; Bronchi; Bronchoalveolar Lavage Fluid; Carrier Proteins; Caspase 1; Cells, Cultured; DNA, Mitochondrial; Epithelial Cells; Heterocyclic Compounds, 4 or More Rings; Humans; Hypersensitivity; Inflammasomes; Inflammation; Interleukin-1beta; Intracellular Space; Lipopolysaccharides; Lung; Male; Mice; Middle Aged; Mitochondria; NLR Family, Pyrin Domain-Containing 3 Protein; Ovalbumin; Peroxidase; Reactive Oxygen Species; Sulfones; Trachea